Hand brake



HAND BRAKE Filed July 17, 1936 May 16, 1939.

I5 Sheets-Sheet 1 Q Q 5 I INVENTOR Rigard WBurnez t ATTO RNEYS y 6,1939. R w BURNETT 2,158,055

HAND BRAKE Filed July 17, 1936 3 Sheets-Sheet 2 INVENTOR iiicgardWBurnezt W M wmp ATTORNEYS y 1939- R. w. BURNETT 2,158,055

HAND BRAKE Filed July 17, 1936 3 Sheets-Sheet 3 y INVENTOR 4g Ricgard WBurnett 40 M M 9 ATTORNEYS Patented May 16, 1939 UNITED STATES PATENTOFFICE 1mm) 1mm Richard w. Burnett, cliimo, 111. Application July 17,1955, Serial No. 91,059 1i Claims. (c1. lac-81.1)-

This invention relates. to railway car hand brakes.

One of the objects of this invention is to provide asimple, inexpensiveand practical hand brake mechanism which is well adapted to meet thevarying conditions of practical use. Another object is to provide a handbrake mechanism of the above character which is efllcient, durable andreliable under conditions of rigorous use. Another object is to providea hand brake mechanism of the above character which is compact andrelatively light in weight and which may be easily operated with amaximum of safety. Other objects will be in part obvious and in partpointed out hereinafter.

This invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts, as will beexemplified in the structure to be hereinafter described and the scopeof the application of which will be indicated in the following claims.

In the accompanying drawings. in which is shown one of the variouspossible embodiments of my invention, 4

Figure'l is a front plan view of the mechanism positioned within thehousing, of which portions are broken away;

Figure 2 is a vertical-sectional view taken along line 22 of Figure 1;

Figure 3 is a horizontal sectional view of the housing taken along line33 of Figure 2;

Figure 4 is an enlarged plan view of some of the parts shown in Figure1;

Figure 5 is an enlarged plan view similar to Figure 4 but showing theparts in different positions;

Figure 6 is a sectional view taken 66 of Figure 5;

Figure 7 is an enlarged front plan view, similar to Figure 5, of amodification of my construction; and,

Figure 8 is a sectional view taken along line 88 of Figure 7. 7

Similar reference characters refer to similar parts throughout theseveral views of the drawmgs.

Referring now to the drawings in detail and to Figure 2 in particular,the handbrake mechanism is mounted in a. housing generally indicated atl0 which preferably comprises a back plate generally indicated at H anda front plate generally indicated at l2. Front plate l2 preferably has arearwardly extending flange l3 (see also Figure 1) formed thereon whichabuts along line against back plate II and extends around the outeredges thereof, having an opening Illa along the lower edge of thehousing, as may be seen in Figure 1. Front plate I2 is attached to backplate H in any suitable manner andthe housing is suitably secured tothe'side wall of a railway 6 car.

In the lower portion of the housing, and preferably mounted uponmachined lugs l4 and I5 (Figure 2) which are preferably integral withand project from plates II and I2 respectively I 10 provide a large gearl6 which is preferably formed integrally with a winding drum l1.Positioned in the upper part of the housing above gear 16 is a shaft I 6preferably supported in the housing by a journal I9 and a bearing 20formed in plates 15 II and I2 respectively. Shaft l8 preferably hasintegrally formed therewith a pinion gear. 2| which meshes with drumgear l6; shaft l8 preferably having one end 18a extending through frontplate l2 of the housing to provide a mount- '20 ingfor a hand wheel 22.Hand wheel 22 'is so secured to shaft l8 that rotation thereof istransmitted through pinion gear 2| and gear l6 to the winding drum IT.The winding drum in turn is operatively connected to the brake rigging(not 25 shown) of the railroad car by a chain, the end link 23 of whichis shown as connected to wind- 'ber 26 comprises a pawl 21 (Figure 2)adapted to engage ratchet wheel 25, and a tail portion 26 also'adaptedto engage ratchet wheel 25 to 40 retard reverse movement thereof, aswill be described more fully hereinafter. Member 26 has a web 29(Figures 1 and 2) preferably formed integrally therewith, which ispositioned above pawl 21 and extends rearwardly or to the left of mem-46 ber 26 as viewed in Figure 2. V v To the right of part 26, as viewedin Figure 1,

is a shaft 36 which is mounted in housing ll parallel to the pivotalaxis of member 26; Secured to shaft 36 and positioned externally of thehousing I6 is a tripping lever 25 (Figures 2 and 3). Pivotally mountedupon shaft 36 is a tripping cam generally indicated at 3| which has apair of jaws 32 and 33 extending to the left of its axis as viewed inFigure 1, these jaws be- 66 wheel 25. If the tripping cam is'movedcountera clockwise, Jaw 32 engages the upper surface .of web 23 to movethe pawl into engagement with the web.

.A recess N is provided in triPP 8 cam 3|, ad- Jacent shaft 33, andintegral with shaft 33 I provide a lug 33 which moves freely in recess33 until it abuts against one end 34a or the other end 3: thereof. Thuswhen tripping lever 35 is moved clockwise, as viewed in Figure i, thereis a certain amount of free or lost movement before lug 33 abuts recessend 33a to cause lower jaw 33 to enga e web 23. similarly if thetripping lever were moved counter clockwise to efiect an abutmentbetween mg 33 and recess end 34b causing the pawl and ratchet todisengage, there would be a certain amount of free or lost movement ofthe lever before the upper Jaw of the tripping cam forced the pawl intoengagement with the ratchet,allofwhichisforapurposetobemore fullydisclosed hereinafter.

- Referring to l'igure6, the sides a and :55 of ratchel wheel 25 arepreferably beveled and the tail portion 23 of pawl member 23 has twodownwardly extending lugs 31 and 33, the inner surfaces of which arepreferably beveled to substantially the same angle as the beveled sides25a and 25b of ratchet wheel 25. Preferably lugs 31 and 33 are sopositioned upon part 23 that they engage a substantial portion of thebeveled edges of the ratchet wheel while at the same time the undersurface 33 (Figure 6) of member 23 is preferably spaced from the ratchetteeth. Accordingly, referring to Figure 1, when pawl 21 is moved out ofengagement with ratchet 25 by upward movement of law 33, the tailportion. 23 of part 23 moves downwardly upon ratchet wheel 25. If thismovement is continued, lugs 31 and, 33 are forced into frictionalengagement with the sides of the ratchet teeth thus retarding reversemovement thereof.

Member 23 is preferably so proportioned that its natural tendency is toassume the balanced position shown in Figure 5 i. e., to move inaclockwise direction when neither of laws 32 or 33 engages its webportion 23. In this position there is no engagement between the ratchetteeth and pawl 21 and either no engagement or very loose engagementbetween the ratchet teeth and beveled lugs 31 and- 33. In thisconnection, it should be noted that the lost motion referred tohereinabove and the various parts whereby it is achieved coact with thepawl in effecting efilcient and advantageous operation thereof. Forexample, when a brakeman is drifting the car over a hump, the car brakesare generally set a certain amount. Under certain circumstances, however, the brakeman might desire thecar to roll faster, in which event atleast a partial release of 'the brake would be necessary. Such partialrelease is readily effected by moving lever 35 in a clockwise directionas viewed in Figure 1, to re- Y lease pawl 21 from'its ratchetingengagement ratcheting engagement subsequent to release therefrom, andthe car brakes thus may be readengagement from this position is greatlyfacilitated by the-momentum built up during the lost or ineffectivemovement of weighted lever 35.-

That is, with reference to Figure i, when weighted lever 35 is flippedover in clockwise direction, lug

'36 .on lever shaft 3|) is free to travel throughoutthe entire extent ofrecess 34 before engaging end 34a of the recess. During this movementthere is, of course, no engagement between law 33 and web 23. However,when lug 33 abuts recess end- 3la, the potential energy built up by theinertia of the weighted lever during its free travel is immediatelyeffective upon the engagement be'tween jaw 33 and web 23 to snap pawl2I-out of its ratcheting engagement with ratchet wheel 23.

The combined features of the pawl and the above-noted lost motionmechanism effect the further advantage of definite and immediatelyascertainable. control in that the brakeman can immediately determinenot only whether weighted lever 35 is in aposition to set or release thepawl, but also the exact point at which such release or engagement maybe effected.

In operation, if the user desires to set the brakes, he throws lever 35'to the position shown in Figure 1. when in this position, jaw 32presses downwardly upon web 29 forcing and holding the pawl inengagement with ratchet wheel 25. Then hand wheel -22 is whirled in aclockwise direction as viewed in Figure 1, causing gears 2i and i8.to-rotate the winding drum l1, and operate the brake rigging (notshown) through chain 23. The pawl 21 (Figure 1) at this time is held inengagement with ratchet wheel 25 by the weight of lever acting throughcam 3i to prevent reverse movement of the parts. when the user decidesto instantaneously release the brakes, the lever is moved clockwise (Flre 1). Referring now to Figure 4, lever 35 ves freely to the right untillug 33 engages end 340 of recess 34. At this time the lever ispositioned as shown in Figure 4. Further movement of the web 23, forcingpawl 21 out of engagement with ratchet wheel 25. It should be noted thatby continuing the movement of the lever in this same direction, jaw 33continues to bear upwardly upon web 23 causing beveled lugs 31 and 33 onthe tail portion of part 23 to frictionally engage the ratchet wheel.

Thus the user by swinging the lever to the right as viewed in Figure 2releases the mechanism and immediately controls the amount of releasethereof by means of the frictional engagement of the lugs with theratchet wheel. This extremely short interval between the releasing andbraking action prevents the parts from attaining any great speed ofrotation before the braking action of member 26 takes efiect,v and alsoprevents the hand wheel from spinning. In

leverin this direction causes jaw 33 to engage other words, the user atall times has complete control of the releasing of the hand brake.

Because part 26 is unbalanced when pawl 21 is engaged with ratchet 25 asdescribed hereinabove, the pawl can not drop .into engagement with theratchet wheel after it has been released therefrom, without manualactuation. Thus,

excessive shock to the engaging parts is avoided. In order to re-engagethe pawl and the ratchet wheel after release thereof, lever II is movedto the left, as viewed in Figure l, and when lug 36 engages the upperend 34b of recess 34 in the cam, jaw 32 engages web" to force the pawlinto engagement with the ratchet wheel. When in this position, the handbrake mechanism is conditionedfor operation of hand wheel 22 to set thebrakes.

Referring now to Figures 7 and 8 the tail portion 28 of member 26 mayhave a brake shoe generally indicated at 40 pivotally mounted thereinwhich serves as the brake. Shoe 4. preferably has an upwardly extendingprojection 4| (Figure 8) formed thereon which extends into a recess 42formed in the tail portion 20 of member 26. A pin 43 extends through thetail portion and pivotally mounts upwardly extending projection 4itherein. Refen'ing now to Figure 7 the upper portion of projection 4ihas slanting sides 44 and 45 which are in substantial registry with thesides of recess 42 which also slant but preferably at a greater angle.The brake shoe 40 freely pivots about pivot pin 43 but its pivotalmovement is limited by the sides of recess 42.

The lower portion 46 of part 40 has lugs 41 and '48 formed thereon whichare substantially similar to lugs 31 and 3B (Figure 6) and which engagebeveled sides of the ratchet wheel 25 in a manner substantially similarto that described hereinabove. It may now be seen that braking shoe 40is readily replaceable and, in use, adlusts itself to the beveled sidesof ratchet wheel 46.

Thus I have provided a construction including eflicient means forretarding the brake-releasing movement of the mechanism. Further, themechanism has been so constructed that the possibility of shock due touncontrolled engagement of some of the parts has been eliminated. Thisfeature further permits a lighter construction of the various partswhich reduces the weight and cost of the mechanism as a whole. Also, theuser of this mechanism, when releasing the brakes, always has completecontrol over release and engagement of the mechanism.

Thus I have provided a thoroughly durable and eflicient construction inwhich the several objects hereinabove referred to, as well as manyothers, are successfully accomplished.

As many possible embodiments may be made of the above invention and asmany changes might be made in the embodiment above set forth, it is tobe understood that all matters hereinabove set forth, or shown in theaccompanying drawings, is to be interpreted as illustrative and not in alimiting sense.

I claim: I

1. In hand brake mechanism, in combination, means for preventing reversemovement of said mechanism comprising a ratchet and a detent, means formoving said detent out of engagement with said ratchet, and means formedupon said detent to engage the sides of said ratchet, saidlast-mentioned means being adapted to be moved by said second-mentionedmeans into position to retard reverse movement of said mechanism.

2. In hand brake mechanism, in combination, a housing, a memberpivotally mounted in said housing, a ratchet wheel, a pawl formed uponsaid member adapted to engage said ratchet wheel to prevent reversemovement of said mechanism, a pair of beveled lugs formed upon saidmember, said beveled lugs being adapted to engage the sides of saidratchet wheel, and means adapted to move said beveled lugs into and outof engagement with said ratchet wheel.

3. In hand brake mechanism, in combination, a member, a detent. formedupon said member, means adapted to be engaged by said detent to preventreverse movement of said mechanism, a lever, a cam positioned betweensaid lever and said membeFand operatively connected. to said lever andsaid member, whereby movement of said lever moves said detent into andout of engagement with said means, and means formed on said memberadapted to engage the sides of said first-mentioned means upon movementof said lever to retard reverse movement of said mechanism.

4. In hand brake mechanism, in combination, a detent, a member engagedby said detent, means for moving said detent into and out of engagementwith said member, and means pivotally connected to said detent adaptedto engage the sides of said member to retard reverse movement of saidmechanism.

5. In hand brake mechanism, in combination, means to set a brake, meansto release said brake, a braking device comprising a pivotally mountedmember having a part pivotally mounted thereon,

a rotating member, said part being adapted to engage said rotatingmember, and means to force said part into engagement with said rotatingmember when said brakes are released.

6. In hand brake mechanism, in combination. means for preventing reversemovement of said mechanism comprising a ratchet and a pawl, means formoving said pawl out of engagement with said ratchet, the center of massof said pawl being so positioned with respect to its axis of movementthat upon release the pawl moves of its own accord out of engagementwith said ratchet, and means formed on said pawl to engage the'sides ofsaid ratchet when the pawl is moved in ratchet releasing direction toretard reverse movement of the ratchet.

7. In hand brake mechanism, in combination, means for preventing reversemovement of said mechanism comprising a ratchet and a pawl, means formoving said pawl out of engagement with said ratchet, said pawl beingmovable through an arc of less than 90" from its ratchet holding toratchet releasing positions, and means formed on said pawl to engage thesides of said ratchet when the pawl is moved in ratchet releasingdirection to retard reverse movement of the ratchet.

8. In hand brake mechanism, in combination, means for preventing reversemovement of said mechanism comprising a ratchet and a pawl, means formoving said pawl out of engagement with said ratchet, said pawl beingmovable through an arc of less than 90 from its ratchet holding toratchet releasing positions, means formed on said pawl to engage thesides of said ratchet when the pawl is moved in ratchet releasingdirection to retard reverse movement of the ratchet, and operating meansfor said pawl including a hand lever movable through an arc greater than90 to force said pawl into ratcheting position in one direction ofmovement and to effect said reverse retarding movement of the ratchet inits other direction of movement.

9. In hand brake mechanism, in combination, means for preventing reversemovement of said mechanism comprising a ratchet and a pawl, means formoving said pawl out of engagement with said ratchet, means formed onsaid pawl to engage the sides of said ratchet when the pawl is moved inratchet releasing direction to retard reverse movement of the ratchet.and operatinz means for said pawl including a hand lever swingablethroughan arc greater than 90 10. In hand brake mechanism, incombination, a detent, a member engaged by said detent, means for movingsaid detent into and out oi! engagement with said member to selectivelyalter the operative condition of said mechanism, and

means formed on said detent having at least one portion adapted toensure a side oisaid member to retard reverse movement of saidmechanism. 11. In hand brake mechanism, in combination, a detent, amember engaged by said detent,

means for moving'said detent into and out of engagement with said memberto selectively alter the operative condition of said mechanism, andspaced portions formed on said detent adapted to be moved intoengagement with the sides of said member by said means to retard reversemovement of said mechanism.

momma w. mm.

